Why portmaster uses g++ not g++6 nor clang++?

[Koichiro Iwao]

Hi,

I'm building devel/qt5-make by portmaster. Somehow portmaster 
incorrectly detects gcc6 and
uses g++ despite it is actually installed as g++6. If I build it without 
portmaster, clang++
is used and build finishes successfully.

$ pkg info | grep gcc
gcc-ecj-4.5                    Eclipse Java Compiler used to build GCC 
Java
gcc6-6.4.0_7                   GNU Compiler Collection 6
gcc6-aux-20170802_1            Version of GCC 6 with full Ada support
gccmakedep-1.0.3               Create dependencies in makefiles using 
'gcc -M'

# portmaster devel/qt5-qmake
(snip)
===>  License LGPL21 accepted by the user
===>   qt5-qmake-5.10.1 depends on file: /usr/local/sbin/pkg - found
===> Fetching all distfiles required by qt5-qmake-5.10.1 for building
===>  Extracting for qt5-qmake-5.10.1
=> SHA256 Checksum OK for 
KDE/Qt/5.10.1/qtbase-everywhere-src-5.10.1.tar.xz.
===>  Patching for qt5-qmake-5.10.1
===>  Applying extra patch 
/usr/ports/devel/qt5/files/extrapatch-configure
===>  Applying extra patch 
/usr/ports/devel/qt5/files/extrapatch-mkspecs_features_create__cmake.prf
===>  Applying extra patch 
/usr/ports/devel/qt5/files/extrapatch-mkspecs_features_qt__module.prf
===>  Applying extra patch 
/usr/ports/devel/qt5/files/extrapatch-mkspecs_common_bsd_bsd.conf
===>  Applying FreeBSD patches for qt5-qmake-5.10.1
/usr/bin/sed -i "" -e "/DEFAULT_LIBDIRS=/ 
s,\\\\\"\\\\n,\\\\n/usr/local/lib&,"  
/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/configure
===>   qt5-qmake-5.10.1 depends on executable: gmake - found
===>   qt5-qmake-5.10.1 depends on package: pkgconf>=1.3.0_1 - found
===>   qt5-qmake-5.10.1 depends on file: /usr/local/bin/python2.7 - 
found
===>   qt5-qmake-5.10.1 depends on executable: gcc6 - found
===>   qt5-qmake-5.10.1 depends on file: /usr/local/bin/as - found
===>  Configuring for qt5-qmake-5.10.1
/bin/mkdir -p 
/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1
echo 'CMAKE_MODULE_TESTS = -' > 
/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/.qmake.cache
echo 'QMAKE_LIBDIR_FLAGS = 
-L/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/lib' 
 >> /ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/.qmake.cache
Creating qmake...
===>  Building for qt5-qmake-5.10.1
gmake[1]: Entering directory 
'/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake'
g++ -c -o main.o   -std=c++11 -ffunction-sections -g -g  
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake/library 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake/generators 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake/generators/unix 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake/generators/win32 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake/generators/mac 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/include 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/include/QtCore 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/include/QtCore/5.10.1 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/include/QtCore/5.10.1/QtCore 
-I../src/corelib/global 
-I/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/mkspecs/freebsd-g++ 
-DQT_VERSION_STR=\"5.10.1\" -DQT_VERSION_MAJOR=5 -DQT_VERSION_MINOR=10 
-DQT_VERSION_PATCH=1 -DQT_BUILD_QMAKE -DQT_BOOTSTRAPPED 
-DPROEVALUATOR_FULL -DQT_NO_FOREACH 
/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake/main.cpp
gmake[1]: Leaving directory 
'/ssd/tmp/ports/usr/ports/devel/qt5-qmake/work/qtbase-everywhere-src-5.10.1/qmake'
===> Compilation failed unexpectedly.
Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the failure 
to
the maintainer.
*** Error code 1

# make -C /usr/ports/devel/qt5-make
-> builds successfully using clang++

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